Heparin/heparan sulfate is one of the glycosaminoglycans having sulfate groups, and has a basic skeleton composed of serial disaccharides linked each other via β1-4 glycosidic bonds (in the present specification, also referred to as “heparin skeleton”). The disaccharides are formed by binding hexuronic acid (i.e. D-glucuronic acid or L-iduronic acid whose hydroxyl group(s) at 2- and/or 3-position may be sulfated) and glucosamine (i.e. N-acetylglucosamine whose acetylamino group(s) may be substituted by a sulfamino group, and/or hydroxyl group(s) at 6-position may be sulfated) via β1-4 glycosidic bonds when the hexuronic acids are D-glucuronic acids, and via α1-4 glycosidic bonds when the hexuronic acids are L-iduronic acids.
In addition to such glycosaminoglycans as heparin/heparan sulfate, many of proteoglycans, glycoproteins, and glycolipids have sulfate groups, and many sulfotransferases are involved in the biosynthesis thereof. For example, as an enzyme which transfers a sulfate group to a heparin skeleton, JP09-28374A discloses an enzyme (HS2ST) that has activity to transfer a sulfate group to a hydroxyl group at 2-position of hexuronic acid in a heparin skeleton. Moreover, JP08-33483A discloses an enzyme (HS6ST) that has activity to transfer a sulfate group to a hydroxyl group at 6-position of a glucosamine residue in a heparin skeleton. Furthermore, JP2000-60566A and WO 02/000889 disclose related enzymes (HS6ST2, HS6ST3) and a variant (HS6STv) of the HS6ST disclosed in JP08-33483A. Furthermore, J. Biol. Chem., 267 (1992), pp. 15744-15750; J. Biol. Chem., 269 (1994), pp. 2270-2276; J. Biol. Chem., 274 (1999), pp. 22458-22465; and Glycoconj. J., 16 (1999), S40 disclose enzymes (NDST-1, NDST-2, NDST-3, NDST4) each having activity to deacetylate an acetylamino group of a glucosamine residue in a heparin skeleton and then to sulfate it.
Meanwhile, it is known that heparin or heparan sulfate has high affinity to growth factors, and it is known that the affinity to various cytokines or growth factors varies depending on a position and degree of sulfation of heparin or heparan sulfate (Glycobiology, 4(1994), 451 or Glycobiology, 4(1994), 817).
Therefore, it is highly likely that an inhibitor, which inhibits activity of such heparin/heparan sulfate sulfotransferase deeply involved in biosynthesis of heparin, heparan sulfate, or the like, can be applied to, for example, an anti-cancer drug using its anti-angiogenic effect, a cancer metastasis inhibitor using its effect to inhibit adhesion to ECM, an anti-allergic drug or an anti-rheumatic drug using its effect to inhibit heparin synthesis in mast cells in connective tissues.
Known examples of such an inhibitor for a sulfotransferase include chlorate described in Biochem. Biophys. Res. Commun., 150 (1988), pp. 342-348, brefeldin A described in J. Biol. Chem., 267 (1992), pp. 8802-8806, etc. The former inhibits a sulfotransferase by exerting a nonspecific competitive inhibitory effect on the enzyme, while the latter inhibits the enzyme by destroying Golgi apparatus where a sugar chain is synthesized. Therefore, those conventional inhibitors may cause side effects, because specificity of their inhibitory effect on biosynthesis of heparin/heparan sulfate is low and they strongly inhibit not only biosynthesis of heparin/heparan sulfate but also biosynthesis of other glycosaminoglycans, proteoglycans, or glycoproteins, so that it is highly unlikely that they can be used as therapeutic agents for diseases.